feat: return existing client if exists

+ add silent option to return parseable json response
+ add api arg to allow response to be used as-is

client_create.py

+"""
+Create a set of client credentials programmatically or return existing 
+if a client matching the id has already been configured. 
+
+Usage: client_create.py \
+    --id=soar-hydrogen \
+    --name="Hydrogen Interface" \
+    --sub="soar.#" \
+    --api="https://nucleus.noc.ac.uk/soar/api" \
+    [--silent] 
+
+"""
 import argparse
 import json
 
@@ -24,20 +36,40 @@ parser.add_argument(
     default="#",
     help="A rabbitmq topic pattern for the client to subscribe to *=one-word-wildcard #=multi-word-wildcard",
 )
-parser.print_help()
+
+parser.add_argument(
+    "--api",
+    type=str,
+    default="http://localhost:8087",
+    help="The root api endpoint",
+)
+
+parser.add_argument('--silent', action='store_true')
+parser.set_defaults(silent=False)
 
 args = parser.parse_args()
 
-client_model = ClientModel()
+if not args.silent: 
+    parser.print_help()
 
-client_model.add(
-    {
-        "client_id": args.id,
-        "client_name": args.name,
-        "subscription": args.sub,
-    }
-)
+client_model = ClientModel()
 
+# Get existing client if already exists
 client = client_model.find(args.id)
-print("Here is your credentials file:")
+
+if not client: 
+    client = client_model.add(
+        {
+            "client_id": args.id,
+            "client_name": args.name,
+            "subscription": args.sub,
+        }
+    )
+    
+# Add the API endpoint to the credentials file
+client['api'] = args.api
+
+if not args.silent: 
+    print("Here is your credentials file:")
+
 print(json.dumps(client, indent=2))